#include <iostream>
using namespace std;
#include <iomanip>
int main()
{
	int array[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
	int size = sizeof(array)/sizeof(int);//computing the length of array. 
	for (int i=0; i<size/2; i++)//exchange the number two position. 
	{
		int temp = array[i];
		array[i] = array[size-1-i];
		array[size-1-i] = temp;
	}
	
	for ( int j=0; j<size; j++)//output array.
	{
		cout << setw(2) << array[j];
	}
	return 0;
}
